Apparatus for irradiation



APPARATUS FOR IRRADIAT IDN a1 Filed Sept. 21, 1953 2 Sheets-Sheet 1 Origin INVENTOR4 GEORGE c. SUPPLEE MERRILL J- DORCAS ATTORNEY March 26, 1940. e. c. SUPPLEE ET AL 2,195,322

APPARATUS FOR IRRADIATION 2 Sheets-Sheet 2 Original Filed Sept. 21, 1933 INVENTOR GEORGE CSUPPLEE BYMERR/LL J- DORCAS Patented Mar. 26, 1940 2,195,322 g APPARATUS FOR IRRADIAIION George 0. Supplee, Bainbridge, N.,Y., and Merrill J. Dorcas, Berea,hio, assignors of'one-half to' The Borden Company, a corporation of New Jersey. andone-half to National Carbon Company, Inc., a corporation of New York ,Original application September 21, 1933. Serial 690,410., Divided and April 1, 1937, Serial No. 134,286

this application '21 Claims. (cl. 250-49) This application is a division of Patent 2,104,681.

v This invention relatesto irradiation of various substances with radiant energy and especially with energy havingwave lengths corresponding to the visible spectrum and to the ultra-violet.

,It especially-relates to improved apparatus for carrying out such irradiation.

In the irradiation of various substances it often becomes desirable to produce certain changes or 0 changes in certain ingredients of substanceswithout producing other changes or changes in other ingredients to a corresponding .degree. A typical example of this is the irradiation of milk with ultra-violet energy. During this irradiation it is 5v desirable to produce a high degree of biological activation,- and especially anti-rachitic activa-' tion, without producing a disagreeable flavor or odor. It is an object of our invention to devise apparatus to provide means for utilizing any of I 1 the differences in the quality or form of the radiated energy whereby different effects are pro- 'ducedupon the components-of the substance being irradiated. As an example of such a change ref-. erence is made to the efiect of polarizationof the er:ergy analogous to the polarization of light. 1 Due to the reflection of this energy at relatively oblique angles the absorbed energy ischanged in some respect. This change may possibly be a polarization in a plane different from the, plane of polarization of. the reflected energy. As another example of such phenomena reference is also made to the unequal reflection of"energy of varying wave lengths especially at oblique angles. Still another object of our invention is to'devise apparatus which will take advantage-ofthe fact that certain changes in the substance are produced at the surface of the irradiated substance While other changes appear to be produced below I the surface. We believe that -anti-rachitic activation occurs at the surface of the substance, for example milk or whey, being irradiated while changes in the flavor and odor take place below the surface at least to some extent. By causing v.

energy to impinge upon the surface v obliquely it is possible .to shorten the depth to which the irradiated substance is penetrated. In this way a smaller proportion of the total d'epth of irradiated substance is affected by the energy impinging obliquelyupon it than would be the case if the energy impinged normally uponv it.

A further object of our invention is to devise an apparatus for carrying out the improved method of irradiation set forth in Patent 2 1041581. Still another object is to devise an apparatus for carrying out irradiation in a more efiicient manner than has been heretofore possible. These and other objects of our invention will be evident from the following specification having reference to'the accompanying drawings in which: I e Figure 1 is adiagrammatic horizontal cross sec- 5,

tion of a device 'constructedin accordance with one embodiment of our invention; v v Figure 2fis a vertical cross section of this device;

Figure 3 section-of a device illustratinganother embodi ment of our invention; 7 i

Figure 4 isa diagrammatic vertical cross sec-1 tion of a device illustrating afurth'er embodiment of our invention;

face 23 of this device; i Figure 6 is, a diagrammatic plan view of the surface of a modification of the device shown in Figures 4 and 5;

' Figure 7 is a diagrammatic horizontal cross sectio a ther embodiment of our a, ventiony w v Figure :8 is a diagrammatifi vertical, cross sec- I tion of a device illustrating another embodiment l of our invention; and i I Figure a hprizontal section of a device illustrating another modification of the invention. We have observed that when light or other ra-j,

diant energy falls onsubstances atvarious angles the relative effects are not" the same. For example if 'milk is irradiatedwith ultra-violet en ergy various effects are produced. We have particularly investigated the effect on flavor and odor and the biologicalactivation, ie., the increase 35." in anti-rachitic effect. For the purpose of com;

parison 'milkwas exposed for a definite time while spread in a thin flowing film to a given source of ultra-violet energy. During some of the tests the central axis of the light beam fell normally or perpendicularly on the film; During other tests 'thecentral axis of the light beam fell at quite acute angles such as angles of 15 from parallel,.(75 from perpendicular); tests were also made at intermediate angles. In all of the tests some of the light rays fell at an angle, but'in describing the invention reference will be made to I the angle at which the central axis or central pencilof thelig'ht beam strikes the'fllm,it beingimpor,-' tant that none or substantially no light rays strike the film at an angle of 90. In evaluating the teststhe anti-rachitio effect and the organoleptic effect of light falling perpendicularly (90 from parallel) on the film were given an arbitrary value br oo. This does ot mean that the anti rachitic is a diagrammatic horizontal crossvlo I 15. Q Figu re 5 is a diagrammatic plan :viewof the surf,

account for the entire which it was possible to give by prolonged exposure. leptic effect was sumcient to give the milk so pronounced a taste or odor as to unfit it for commercial use. These were simply arbitrary values given to the efiects produced by light falling normally upon the film. Other films were treated at difiereht angles. During these treatments the time of exposure wasthe same, the same source of ultra-violet energy was used and the distance from the center of the fllm to the source of ultraviolet energy was the same. It was found that when the angle was 30 to 50 from parallel the biological eifect or anti-rachitic efiectivenessstill had the value of but the organoleptic effect or the ability of the rays to produce adverse flavor or odor decreased to a value of from 25 to 35. When the impingement angle was even more oblique, about 15, the biological effect of the milk thus treated was still nearly 100 whereas flavor and odor development had a relative value of from 5 to 15. Thus it will be noted that by causing the energy to fall very obliquely upon the film of milk it is possible to vary the relative biological and organoleptic effects and that the biological effect is much greater relative to the organoleptic effect when the energy impinges upon the film at a very oblique angle. The angles at which the energy impinges, are measured from the surface of the film, or, where the surface is curved, from a plane tangent tosaidsurface. Such angles have, for convenience, been designated as angles from parallel. I

The improved result may be due to one ,or more of the following causes although it is not intended tolimit the invention tothe particular causes enumerated. It is known that whenlight is reflected from substances at certain angles the light so reflected is polarized in one plane.

It may be assumedthat the light not reflected, i. e., absorbed, is polarized, so to speak, in a plane perpendicular to the plane of the polarized reflected light. The biological effect may be. produced to a considerable extent by the fact that this energy which is absorbed has undergone some change 'similanto that of polarization in light.

Another possible theory is'that the change is due to the unequal reflection of energy of various wave lengths especially at oblique angles. We have determined that energy of various wave lengths is reflected in different amounts when the energy impinges at varying angles on a reflector, especially a reflector consisting of a flowing film of milkor similar substance. Since the thickness of the film is such that less than 10% of the ultra-violet energy is transmitted through the film, it is evident that the energy which is not reflected is absorbed. We have found that there is a sharp drop in the amount of energy reflected in the neighborhood of 2850 A. This indicates an increasing sharp rise in the energy absorbed. Since it is the energy in the region of thiswave length which is believed to be very eflicacious' in biological activation, it appears not improbable that the increased efficiency .of the energy having small impingement angles may be due to some extent to the change in reflection with such wave lengths. At the same time the change does not appear to us great enoughto difference between biological activation and organoleptic effect.

This change in effect may be due to a difference in the place where the changes are made It also does not mean that the organoeffect having the value of 100 was the greatest which give difierent effects. It may be assumed that thebiological activation takes place only at the surface and that organoleptic changes take place both at and below the surface. When the energy falls obliquely on the film of material being irradiated the potential linear path within the substance has the same length but it affects a much thinner layer in the ordinary cases i. e. those inwhich the film is of such a thickness as to absorb substantially all the energy.

We have accordingly conceived the idea that it would be advantageous if the radiant energy used in the treatment of various substances should fall obliquely upon the substance being irradiated. In case the substance being irradiated is milk,'this impingement of the rays at an oblique angle produces a relatively high biological effect in proportion to the flavor and odor effect ascompared with the proportionate effects which would be produced if the energy fell at right angles.- For this reason we prefer to irradiate milk and the like with energy impinging tion. While we have disclosed the use oi specific angles to secure desired results, it is within the scope of our invention to vary the angle as may be necessary to secure other results.

Numerous forms of apparatus may be employed in carrying out our improvedmethod. We disclose a large number of embodiments of our im-' proved apparatus hereinbut the invention is not limited to the particular embodiments shown. In Figures 1 and 2 we show a type of apparatus well adapted for carryingout our improved process. The device consists of a source of energy Ill surrounded by means over which a film of fluid to be irradiated may be caused to flow. In the particular type shown in Figures land 2 the film forming device is composed of a number ofvertically positioned members H, V-shaped in horizontal section, extending outwardly from a cylinder [2. The cylinder is split at l3 to permit of the cleaning thereof and also replacements and adjustments of the source of ultraviolet energy. The walls of the V-shaped members do not come together, but are provided with a flat or rounded surface near their vertices in order that they may be easily cleaned; The liquid to be irradiated is supplied to the top of these surfaces and is allowed to flow downwardly under the influence of gravity. While the milk may flow the entire height of the film-forming means, we have found it convenient to use a device having two or more times the height necessary togive the fluid the necessary period of irradiation. In this manner we are enabled to treat two streams or more of fluid simultaneously with a single source of energy. In carrying out this treatment of two streams simultaneously we provide a distributing member 14 at the top and a similar, distributing member l5 half way down; Collecting members l5 and I! falls obliquely upon the films on the walls. The

angle of impingement of the beam of energy may be selected to give any particular desirec r I amass; effect. Itis. tdbeunderstood ordinarily nofiuid' would be passed over the flat-spaces attheven tices of the V-sha-ped membersor atthe surfaces connecting thebases. 'Ihis can easily be provided for by making. blank spaces-in the distributing members. and It. .Thus allthefluid is irradiated with energy which impinges obliquely thereon. In certaincases the a. count of'energy reflected from one surface of the V-shaped memher to the opposite surface may be su flicient to cause-an undesirable flavor or odorin case of milk. If positiveprotection is required to preventthe reflection from-ione'surface normally onto an adjacent surfacewe may provide baffles of. non-reflecting in Figure 1.

I materials such as shown at I8 In addition was form-of irradiating device shown in Figures'l and 2it is possible toemploy a plurality of separate surfaces as shown in Figure 3, which is a diagrammatichorizontal section of another'type of irradiation device. In

this type of device a plurality of surfaces2| are" arranged about alight source at such an angle that the radiation will fall obliquely onthe film 1 of milk flowing downwardly 'overthe screens.

The surfaces are soplaced thatgthe outer edge of the effective area of eachsurface is just clear of the shadow cast jacent screen. v v

The milk or other fluid to'be irradiated flows downwardly over the surface under the influence of gravity. Themilk may travel downwardly over j the entire. area; .the surfaces being supplied at the top by asuitable collecting means by, the inner edge of the addifferent streams of "milk in parallel may flow over different portions of the surfaces as shown in Figure-2. Normallythe surfaces are so arranged that one passing of the milk over a surface gives sufiicient irradiation.

In addition to forms of irradiating devices in i which the milk flows downwardly'over vertical boards or'screenszwhichcare so positioned with respect to vertical radial planes": passing through the source of illumination.that energy falls'obliquely on'the film, we'maytmakeiprovision for surfaces which are" not: vertical and in which the desired oblique impingement, ofthe radial energy is secured vby arranging-the surfaces at the proper angle with respect-to, thehorizontal. Thus in Figuresaand 5 we show a device illus-l tratingr an embodiment of our invention con;

structed to obtain" the desiredeffects in the manner'set forth'above. In this device a plurality of frustrums' of cones are'provided. These conical'memberswhich are designated as f23 are arranged about a sourceaoffradian't energy 24. In those members which are not "considerably below the source of energy the vertex is pointing downward. In those which are, considerably below the source of energy the vertex ispointing upwardly. In this manner it is provided that the energy emitted at 24 impinges obliquely upon the surface of the film on the members23. Thelfluid to be irradiated isf;;supplied. at the upper part of the members 23 by suitable distributing means 25 and is collectedby suitable collecting means 26. It should benoted that in some cases the distributing meansis at the outside of the device and the collecting means inside but in certain other cases this isreversed.

The purpose of this isof course to provide for ;he flowof the liquid being irradiated under the nfluence of gravity at all times It is to be noted n certain cases the path of travel of 'the liquid aeing irradiated isjgreaterthan the others, {I'hus ,fllm of material to energy on the irradiating surface.

because the inclination ofsome of the irradiated surfaces is greater. than in others,- consequently the liquid will flow faster overthesei In such cases thepathoftravel is made longer in order that the. total time or irradiation may be approximately the same. However, should it be desired .to compensate for the varying dis: tance from the-source of energy we may make the upper .and lower surfaces slightly longer to give. the fluid flowing over the surfaces at slightly greater period of irradiation.

as shown in Figure 6.. Here part of the radiation may be wasted device is simplified.

While we. have shown embodiments of our inventicn in which the source of ultra-violet energy I "20 is: completelysurrounded by means for forming a filmor thin layer of substance to be irradiated, our invention is' notso" limited.v In Figure -7 We show a cross section of, a device embodying another form. of our invention. 'In this form the surfaces overwhich the fluid to be irradiated flows consists of fa. number of vertically ar-.

ranged sections 3lwhichare so placed with,re-

energy from the"so"urce falls obliquely on the I be irradiated onthe surfaces 3!. In "order toutilize all the. energy emitted by. the source 32 a reflector 33 is provided. We may also provide a series of baflles 34 to prevent reflected energy from impinging perpendicularly upon the film of fluid being ir-- necessar'y'i'n most cases. Wehave conducted experiments on the use of reflected. energy and well to those obtained when direct raysar'e uti- -lized, andwhen the degree of intensity ofthe reflected rays are taken into account.

' spectato a source of radiant energy 32-that 3. radiated. However we domnot regard this as u have found the relative results to conform fairly Y Various. embodiments of 'our invention may be used to. employ reflected energy, thus in Figure 8 we show a vertical cross section of a device for utilizing reflected energy. The substance to be irradiated is formed'in thin: layers on a surface M .Iwhich, is conveniently" cylindrical. The' source of energy is at 4 2. 'I'he energy is refle'cted'by a plurality offr'eflectors 43 onto "the surfacey ll. In the embodiment shown the reflected energy impinges obliquely upon the irradiated substance. While we prefer to usethis constructionwe do not regard it as absolutely necessary in cases where the energy. strikes the reflecting surface obliquely. Itis to be' Understood. that the irradiating surface is provided 7 with distributing and collecting means for sup plying the fluid thereto and. collecting it there-. from and that the reflecting surfaces are spaced from the-irradiating surface substantially-to per:

mit" an unobstructed flowof the fluid to be irradiated between the irradiatingsurface'andthe reflecting surface. I

:In Figure 9 we show another form of device for ingsurface 45 surrounding a source of energy 46, VA plurality of vertical plates 41 serve as reflecting surfaces for reflecting the energy onto the fluid on the irradiating surface. It will be noted that in the embodimentsshown in Figures 8 v and}? the reflecting surfacesserve as screens for preventing the impingement of unrefl'ected as v a utilizing reflected energy. In this. embodiment of our invention'we utilize a cylindrical irradiatgeneral', our improved apparatus is useful with"heterogeneous substances by which we mean'substanoes containing dispersed or susfluid therefrom,

pended particles in amedium of different physical characteristics, or solutions.

We claim: v X 1 1 Apparatus for" the application of radiant energy-to fluids comprising a source of ultraviolet radiant energyand'me'ans providing a substantially vertical surface over which the fluid is adapted to flow in a relatively thin film, said surfacebeing so disposed with respect to the source of energy that all theenergy impinges upon the surface ofth-e fluid on said'surface at angles less than substantially.- 60 from parallel. I '2. In a device *for irradiating fluids with ra diant energy, the combination of a source of radiant energy and. a plurality of means for simultaneously forming substantially vertical films of a fluid to'be irradiated, said means being arranged circumferentially about said sourceo-f energy'and at such angles that most of the energy impinging on the surfaces of said films impinges atangles less than substantially 60 from'parallel.

"3. A device inacccrdanc'e with claim 2 in which said film-forming means'are plates so arranged that their surfaces form V-shaped surfaces.

4. A" device for the irradiation of fluid with ultra-violet energy comprising a source of radiant energy, a pluralitybf conical surfaces adapted for flow thereover of fluid tobeirradiated surrounding said source of energy,said surfaces havmg their imaginary vertices'in 'avertical line passing through the sourceof energy and being so'arran'ged with respect to the source of energy that most of the'energy impinges on said'surfaces 'at angles less than substantially 60 from parallel, said conical surfaces including .at least one such surface for'flow' of liquid toward said source, and at least one such surface for flow of liquid away from'-:said.source, all surfaces for flow toward saidsource being positioned above all surfaces for flow away from said source, and means for supplying each of said conical surfaces simultaneously with fluids to be irradiated. 5. A device for applying radiant energy to fluids comprising a plurality of vertical members, means forsimultaneously supplying fluid to be irradiated to one of the surfaces of each of said members and means for collecting the irradiated a.source of radiant energy adjacent said members, said members being so disposed with respect to the source of radiant energy thatmost of said energy impinges on s'aidsurfaces at angles less than substantially 60 from parallel;

6.1m adevice for irradiating fluids withfradiant energy, the combination of a source of ra-' diant energy and a plurality of means for forming substantially vertical films of a fluid to be irradiated," said means comprising V-shaped surfaces over which the fluid to be irradiated may flow,said means being arranged circumfere entially about said source of energy with the open ends of the V -shaped surfaces toward the source of energy,the angles of such surfaces being such that most of surface of said films atangles less than substantially 60 from parallel, said means including baffles between the sides of each V-shaped surface. i -"I. A device forthe irradiation of fluid with ultra-violet energy comprising a source of radiant energy, a plurality "of conical surfaces surrounding said source of energy and means for supply the energy impinges on the cal surfaces towardsaid source of energy, said surfaces having their vertices in a vertical line passing through the source of energy and being so arranged with respect to the source of energy that substantially all of said radiant energy impinges on saidsurfaces at angles less than 60? from parallel. a I

8; A device-in accordance with claim 5, in which the disposition of the members is such that none of the energy impinges normally on said surfaces. I

'9. A device for the irradiation of liquids with radiant energy comprising a source of radiant en-' ergy, a plurality of fllm-fcrmingxsurfaces' surrounding said source, all of said surfaces having their outer and inner edges respectively in arcs of coaxial cylindrical surfaces with their common axis passing through the energy source, and means for supplying each of said surfaces simultaneously with fluids to be irradiated.

10. A device in accordancewith claim 9, 'in which film is adapted to be form-ed cnpairs of adjacent, substantially vertical. faces, each surface of said pair generally facing the other surface of said pair and said source,

11. A device in accordance with claim 9, in which the film is formed on substantially vertical surfaces facing the same general direction about said source. Y

12. A deviceforiithe. irradiation of liquid with radiant energy comprising a source of radiant energy, a plurality of conical surfaces adapted to receive radiant energy from said source surrounding said source-of energy. and means for supplying liquid to be irradiated to and collecting it from said surfaces; said surfaces having their vertices in a vertical line passing through the energy source, eachof 'said'vertices being below saidenergy source; v r

' 13. In a device-for irradiating liquids with radiant energy, the combination of a source of ra-' diant energy; aplurality of, surfaces, having a V-shaped cross section for forming films, of liquid to be irradiated; said surfaces being disposed with the open end ,of the V toward the source of energy; and a baffle for each of said surfaces, within said I, saidwbafiles extending in a direction to intersect said source of energy if produced.

14. In' a device for irradiating liquids with radiant energy, the combination of a source of radiant energy and means for supporting liquid to-loe irradiated in thin films; said means comprising a plurality of substantially vertical plates with their inner and outer edges respectively in arcs of co-axial cylinders, said plates diverging inwardly; and a baflle between each pair of plates so arranged as to prevent'reflection of energy from one plate to the other but without intercepting energy-impinging without reflection on said plates.

15. A device in-accordance with claim 13, in which the surfaces are so arranged that most of the energy impinges on the surfaces at angles less than substantially 60 and none of it impinges normally. I

16. ,A device in accordance with claim 14; it which said plates are so disposed that most 0: the energy impinges'thereon at angles less thar substantially 60? and none of it impinges nor mally.

1'7. An apparatus for irradiating fluids with ra diant energy comprising a source of energy, 1 plurality of film forming members adapted t form a plurality of fluid films so-disposed rela tiveto said-source and each other that substans I tially all the energy impinging, on the surfaces of said films impingesxat-angles less than substantially 60 from paralleL'and means for initially supplying eachof saidfilm forming mem "-bers simultaneously with fluidsto be irradiated,

said film forming members being in a nonseries flowrelationship with respect to the i'luid'to be a supplied thereto.

v "being arranged about said source of energy at 16 18. In an apparatus for irradiating liquids with radiant energy, the combination of a source of radiant energy, a plurality of surfaces for forming films of liquid to be irradiated, said surfaces such angles that most of the energy; impinging on said films impinges at angles less than substantially 60 from parallel and none of it im:

pinges normally, and means for initiallysupplying each of said surfaces simultaneously with fluid to be irradiated, said surfaces being in a non-series flow re'lationshipywith respect to the fluid to be supplied thereto.

] 19. Apparatus for the application of radiant energy to fluids comprising a source of radiant energy, surfaces adapted toform relatively thin films of liquid for exposure to said energy, said surfaces. being ,sodisposed to said source of radiant energy thatnone of the rays impinge nor-:

mally on theffilms of liquid, and means for initially supplying each of said; surfaces simultaneously with fluids to be irradiated,- said surfaces being in a non-series flow relationship with respect to the fluid to be supplied thereto.

20. Apparatus for. the application of radiant I energy to liquids comprising afsource of ultraviolet radiant energy, and substantially vertical ,means' providing a plurality of surfaces adapted for flow of liquid downwardly thereoverin relatively thin films, said surfaces being. in multiple flow relationship toyeach other, with respect to the liquid flowing over such surfaces, said sur-] faces being so disposed with respect to the source of energy that substantially all of the energyJ-impinging on the surfaces of said films impinges at angles'less than substantially 60 from parallel. 21. "A device in accordance with claim 2 in which at least one of said'film forming means is disposed substantially above another of said" film forming means. I

GEORGE, C. SUPPLEE.

MERRILL J. DORCAS. 

